Efficacy and Safety of Radical Prostatectomy (RP) With or Without Salvage Radiotherapy Versus RP With Extended Pelvic Lymph Node Dissection for Localized Intermediate- and High-risk Prostate Cancer With a Briganti Nomogram≥7%

Inclusion Criteria: * Provided signed and dated informed consent form. * Be male aged 18-80 years at consent. * Commit to protocol compliance and complete all study procedures. * Medically fit to tolerate interventions, including PSMA PET imaging, RARP, pelvic radiotherapy. * Diagnosis of localized intermediate/high-risk prostate cancer (miN0M0): i. Confirmed by: systematic biopsy + PSA + PSMA PET/MRI. ii. Briganti nomogram (2017)≥7%. iii. Candidate for radical prostatectomy. iv. D'Amico: 1. Intermediate-risk: PSA 10-20ng/mL OR Gleason 7 (ISUP Grade 2/3) OR cT2b; 2. High-risk: PSA\>20ng/mL OR Gleason\>7 (ISUP Grade 4/5) OR cT2c. Exclusion Criteria: * Prior treatments for prostate cancer, including radiotherapy, chemotherapy or endocrine therapy. * Non-acinar adenocarcinoma histology on biopsy. * Preoperative evidence of metastasis: nodal(N1), locally advanced(T3-4), or distant(M1) disease on imaging. * History of pelvic lymphadenectomy or radiotherapy. * Other malignancies within 5 years. * Contraindications to radical prostatectomy or being deemed surgically inoperable upon clinical assessment. * Contraindications to radiotherapy or intolerance determined by radiation oncologists. * Severe allergy to PSMA PET ligands or excipients. * Any other conditions precluding PSMA PET examination.